Wound Healing Flashcards
What is a wound? What’s the difference between a surgical and traumatic wound?
injury that breaks the skin or other body tissues
SURGICAL: cut or incision that is purposely made during surgery, causing minimal tissue damage
TRAUMATIC: sudden or unplanned injury (bites, burns, lacerations)
What is wound healing?
biological process that replaces devitalized and missing cellular structures and tissue layers —> restores tissue after injury
What is the difference between open and closed wounds?
OPEN = penetrating; broken skin and exposed tissue (punctures, surgical wounds/incisions, thermal wounds)
CLOSED = damage to tissue under intact skin usually secondary to blunt trauma, where injured tissue is not exposed, but there can be bleeding and damage to underlying muscle/internal organs/bones (contusions, hematomas)
What are abrasions?
skin rubs or scrapes against a rough or hard surface, causing a loss of epidermis and a portion of the dermis usually with no significant bleeding
(scrub and clean to avoid infection)
What are lacerations?
cut or tear in skin that can vary in severity and depth, with rapid and extensive bleeding if really deep
What are punctures?
small hole or wound caused by a long, shart object (nail, needle, teeth, knife) with minimal skin damage, but underlying tissue damage may be severe
(higher risk of subsequent infection by contamination introduced at the time of puncture)
What are avulsions?
partial or complete tearing away of skin and tissues beneath, typically caused by crushing accidents, explosions, gunshots, or head-on collisions, and tends to bleed heavily and rapidly
(traumatic injury where one or more pieces of tissue are torn and detached from the body)
What are contusions?
blunt force trauma that doesn’t break the skin, but causes damage to the skin and underlying tissue —> blood leaks from vessel within the skin or from deeper tissues (type of hematoma)
What are hematomas?
collection (pooling) of blood outside of a vessel
What are crushing injuries?
force applied to an area of the body over a period of time, commonly seen in bite wounds
What are degloving wounds? Where are they most common?
avulsions or detachment of the skin and subcutaneous tissue from the underlying muscle and fascia secondary to a sudden shearing force applied to the skin surface
forelimbs
What 3 factors tend to affect how well or quickly a wound can heal?
- environment, temperature - moisture = high microbe growth
- patient’s overall health
- drug treatments - supplements and treatment protocol
What are the 3 phases of wound healing?
- INFLAMMATORY - immediately after injury; mainly directed at minimizing blood loss from the injured area by hemostasis (influences treatment)
- PROLIFERATIVE - 3 to 5 days and lasts several weeks; granulation contraction and epithelization of injured tissue
- REMODELING - 3 weeks and lasts weeks to months; formation of new collagen, wound tissue strengthening, scar formation
What are the inflammatory steps of Phase 1 of wound healing?
vasoconstriction —> platelet aggregation —> clot formation —> vasodilation —> phagocytosis
There is no “golden rule” fo going about wound care, but what 6 basic steps should occur?
- prevention of further wound contamination (lavage)
- debridement of dead/dying tissue
- removal of foreign debris and contaminants
- provision of adequate wound drainage
- promotion of viable vascular bed (blood/nutrition to viable tissue)
- selection of appropriate method of closure
In what 4 ways are wounds managed?
- patient assessment
- wound assessment
- wound cleaning and debridement
- wound management plan
What 8 things should be considered in the patient assessment for wound care?
- hemodynamic stabillity - stabilize hypotension, murmurs, tachcardia/bradycardia, and arrhythmias
- hydration - start IVF or SQ fluid if patient is dehydrated
- pain sensation/neuro function, esp in limb injuries
- body condition
- organ dysfunction
- anemia
- sepsis - left shift, toxic/degenerate neutrophils, hypo/hyperglycemia, prolonged clotting
- provide analgesia
What are clean wounds?
wounds involving non-contaminated, non-traumatic, and non-inflamed surgical sites, where the GI, urinary, or respiratory tracts are NOT entered
- aseptic technique is maintained
- tissues are not predisposed to infection
What are 4 examples of clean-contaminated wounds?
- wounds where the GI tract, urinary, and respiratory tracts are entered under controlled conditions without contamination (no spillage of organ contents)
- acute traumatic wound that has been cleared
- minor break in sterility (perforated glove)
- placement of a drain in a clean wound
What are contaminated wounds? 4 examples? How should they be treated?
surgery where Gi contents of infected uring is spilled into an open cavity
- major breaks in aseptic technique
- open fractures
- penetrating wounds
- new open traumatic wounds/lacerations
antibiotics, lavage, debridement
What are dirty/infected wounds? 3 examples? How are they treated?
wounds that are heavily contaminated/infected commonly including foreign material and resulting in purulent discharge
- abscesses (common result of cat fights)
- traumatic wounds > 12 hours after injury
- surgery where hollow organ/viscera is perforated or fecal contamination occurs (gross spillage of contaminated body contents) - intestines, pyometra, gallbladder
antibiotics, lavage, debridement, drainage +/- bandage
In what 6 ways should a wound initially be approached? What should be avoided?
- protect with occlusive bandage (esp if wound care will be delayed)
- provide analgesia
- drug therapy (antibiotics)
- wear gloves to avoid contamination
- fill wound with WATER-SOLUBLE lubricant to clump hairs
- clip and clean with large margins
DON’T use scrub in wound bed - use solution!
What are the main 2 purposes of lavaging a wound?
- keeps tissue hydrated
- reduces bacterial contamination by removing gross contamination and necrotic debris
What is used to lavage wounds? What should be done after? What wounds are not lavaged?
copious amounts of warm fluids (saline, LRS, chlorhexidine solution) —> never enough - “dilution is the solution to pollution”
culture
puncture wounds
What are the 4 types of initial debridement?
- SURGICAL - freshening of edges with a scalpel blade to cause active bleeding, usually only indicated in preparation for wound closure
- CHEMICAL - enzymatic ointments ($$$)
- MECHANICAL - bandaging wounds to trap devitalized tissue in the primary layer (painful! cheap material)
- BIOSURGICAL - maggot therapy
When is it most appropriate to use chemical (enzymatic) debridement?
patients that are poor anesthetic candidates (murmur, unstable) or only need minimal debridement (small wound)
What is strikethrough?
bandage is no longer white and is soaked, meaning it must be changed
What are 5 examples of what should be debrided?
- contaminated SQ fat
- shredded fascia
- macerated muscle
- devitalized skin
- skin edges (3-5mm)
What are 6 examples of what should not be debrided?
- direct cutaneous vessels
- hypodermis
- cutaneous muscle
- bones with attachments
- ligament attached to bone
- nerves
(+ other vital structures)
What 9 things determine the management of closure plans?
- wound classification
- time since injury
- location of wound
- degree of contamination
- degree of tissue trauma
- extent of tension or dead space
- blood supply to wound
- clinical condition of patient
- results after debridement and lavage
What is first, second, and third intention?
FIRST = primary closure within a few hours (6-8 hrs)
SECOND = non-closure, contraction, epithelialization
THIRD = delayed primary closure (18-24 hours) before granulation formation
What is secondary closure? Epithelilalization?
SECONDARY CLOSURE = after granulation tissue is present
EPITHELIALIZATION = healing of partial thickness wounds, including first-degree burns and abrasions
What is first intention? What are 2 examples? What are the 4 most common outcomes?
primary wound healing or closure that’s the best choice for healthy wounds in well-vascularized areas
- wound closed within 24 hours of injury with suture or staples
- clean (surgical) or “fresh” traumatic wounds after it’s been cleaned (clean-contaminated)
minimal edema, no local infection/serous discharge, minimal scar formation, rapid healing
In what 4 situations is it common for contaminated wounds to be closed?
- aggressively debrided
- good blood supply
- no evidence of established infection
- <6hrs old
What is third intention? When is this the best option?
delayed primary closure where wounds are sutured closed before granulation tissues form —> moderate to marked tissue edema, significant swelling and/or skin tension
infected or unhealthy wounds that are too contaminated for primary closure (appear clean and well-vascularized within 3-5 days)
What are 4 examples of wounds that should be closed with third intention?
- contaminated or infected wounds
- extremity wounds
- wounds from blunt trauma
- older wounds with questionable viability
What is secondary closure? What may be required? In what wounds is this recommended?
wounds closure >5 days after injury, where medical management of the wound is done before it is surgically closed
- wound cleared of infection
- excision of epithelialized edges and granulation tissue
infected wounds or large wounds
What is second intention? What is secondary closure?
secondary wound healing or spontaneous healing where the wound if left open
the event where a wound recovering via second intention is required to be closed
When is second intention recommended? What is a major risk?
when the patient is a poor anesthetic/surgical candidate, has infected wounds, or has large wounds
contracture formation - proud flesh in horses (granulation tissue grows out from wound and protrudes)
What are 4 examples of wounds left to heal with second intention?
- moderate to small trunk wounds/burns
- abscesses (lavage can never clear all bacteria and they should not be sutured in)
- distal extremity wounds (not a lot of skin)
- fistulae
What is the golden period? How should wounds be healed after the golden period?
wound treated within 6-8 hours of injury, where bacterial levels have not multiplied to critical numbers yet and the tissue has not become infected
infection is likely - do not close
In what 4 ways can tissue viability be measured?
- attachment
- color
- texture
- temperature
What are 7 uses of bandages?
- covers drains and wounds
- reduces dead space and edema
- mechanically debrides wounds
- vehicle for antiseptics
- immobilization
- cleanliness
- holds dressing in place
What are the 3 layers of bandages?
PRIMARY (dressing) - directly on wound and made of gauze or mesh material that promotes early healing and allows fluid to pass through secondary layer to prevent tissue from drying out
SECONDARY - made of cast padding or roll cotton; absorbs fluid, pads the wound, decreases dead space, and supports/immobilizes limb
TERTIARY (outer) - adhesive tape or elastic wrap (vet wrap); provides pressure, holds inner layers in place, and protects from environment
What is hydrophilic foam? What 2 things does using this allow for?
hydrophilic dressing used to maintain a moist wound environment and lower adherence of bandages to wound surface
- decreased bandage changes
- decreases tissue maceration
(high fluid-handling capacity)
On what wounds is sugar commonly used? What are 2 effects?
exudative wounds (1cm thick layer, with SID-TID bandage changes)
- decreased bacterial proliferation
- promotes debridement and granulation/epithelialization
What 2 effects does manuka honey have on wounds? What are some advantages and disadvantages?
- promotes debridement, granulation, and epithelialization
ADVANTAGES: easy to acquire and store, cheap
DISADVANTAGE: messy
In what 3 situations are drains placed in a wound? How long do they typically stay?
- dead space cannot be eliminated
- fluid accumulation is likely
- infection present
3-7 days
What are the 2 types of drains?
- PASSIVE: relies on gravity, pressure differentials, or overflow to remove fluid or gas; fluid exits around the tube at the incision site, pointing downward
- ACTIVE: apply an artificial pressure gradient to pull fluid or gas from a wound, involving suction
How are cuts and tears (lacerations) typically managed? What must be treated first?
complete closure
damage to muscles, tendons, or other tissue
How are degloving injuries typically managed?
bandaged
How are puncture wound typically managed?
left open —> explore, underlying trauma
How are abscesses typically managed?
- establish draining
- lavage copiously
- warm compresses
- antibiotics
How are open fractures typically managed?
- rapid wound care and culture
- bandage/splint
- antibiotics
- analgesics
- surgery consultation
What are 4 common complications in wound healing?
- SEROMA - layered wound closure, drains
- INFECTION - debridement, antimicrobials, +/- supportive care
- DEHISCENCE - tissue viability, closure technique
- FAILURE TO HEAL - patient status, closure method
